1. Field of the Invention
The present invention relates in general to rocker arms for internal combustion engines and more particularly to a metal rocker arm of the kind having a ceramic tip in the place for contact with a cam.
2. Description of the Prior Art
It is known to mount a sintered metal or hard metal tip on the section of a rocker arm for contact with a valve operating cam. The sintered metal or hard metal tip is soldered or brazed to the rocker arm proper by induction heating.
In place of such a sintered metal or hard metal tip, it is also known to utilize a tip made of ceramics, as silicon nitride, silicon carbide or sialon, that is light in weight and has an excellent heat and wear resistivity, in order to cope with a recent automotive engine trend to high performance. In soldering or brazing of such a ceramic tip, it is necessary to utilize a continuous furnace together with a conveyor since the ceramic tip cannot be heated to a desired high temperature by induction heating.
During conveyance by the conveyor, the ceramic tip and the soldering or brazing metal are liable to move relative to each other due to vibrations of the conveyor. Such movement may cause inferior or faulty producs, for example, may cause cracks in the ceramic tip.